Websites aren't loading properly, red X's appear where images should be, panels are misaligned, etc.


This article applies to:

  • R3000

Question:

Websites aren't loading properly, red X's appear where images should be, panels are misaligned, etc.

Reply

Web pages can sometimes contain images and objects that are served by a completely differnt URL or domain. If the initial page request is valid (i.e. not blocked), then the main page will load as normal. However, if the images and objects on that page are served by a different site and that URL is in a blocked category, then the R3000 will send block pages for each of the subsequent object requests.

For example, Mapquest's main page is www.mapquest.com, which is categorized in the 'Reference' library. However images on that page are served by img.mqcdn.com, which is contained in the 'Image Servers & Image Search Engines' library under the wildcard URL "*.mqcdn.com". So in this example, if you are allowing 'Reference' but blocking 'Image Servers', a request to mapquest.com will load the main page, but all images will be block. Which will probably appear as red X's on the page.

The following troubleshooting steps can be taken to determine if this is the cause for your issue:

  • Check the raw shadow.log traffic output (System Tab > Diagnostics > View Log File): This log contains all recent hits and is viewable up to the last 500.
  • Run a Real Time Probe (Reporting Tab > Real Time Probe): Since you can't single out any data from viewing the shadow.log file, a Real Time Probe can be used to see the traffic for a particular workstation in real time.
  • If you have an Enterprise Reporter, run recent reports and check if block pages were indeed sent for those page requests.
All these should give you the information you need to make the appropriate changes to your filtering profile.
This article was previously published as:
8e6 KB 276575

Last Modified 1/21/2008.
https://support.trustwave.com/kb/KnowledgebaseArticle12385.aspx